"All you need to believe is that we will avoid another recession over the next couple of years," she told Squawk on the Street. "And that is indeed our forecast, even though we see growth has slowed somewhat."

She said the current historically low interest rates have made equities a better investment than bonds, which now also have their share of risk after generations of being perceived as safe.

"It's hard for us to see how bonds can generate the same kind of returns going forward that they have over the last 30 years," she said. "Equities seem to be very attractively valued."

She said she agrees with Goldman economist Jan Hatzius's forecast of the second half being more "difficult" than the first. "We have seen some deceleration in economic activity" after a mild winter that might have "puffed up" seasonal growth in the first quarter, she said.

But slow growth is still growth, and the longer-term trend is to the upside, she said.